Chop the pistachio nuts until quite small. Mix them with the remaining ingredients. Rub the ingredients together until the mixture starts to form clumps. Press against the side of the bowl to bring it together.

Transfer to a board and knead lightly, then roll into a sausage shape. Wrap and chill in the freezer for 30 minutes.

Preheat oven to 180C/gas mark 4. Grease a large baking sheet. Slice the chilled log into discs about 5mm thick and place on the baking sheet. They do not spread in cooking so do not need to be placed far apart.

Bake for 13-15 minutes until they start to go golden around the edges. Cool on a wire rack and store in an airtight tin.